Re: [Linux-usb-users] [2.6.10-rc2] ehci_hcd causes oops after some use of usb harddisk

[Jan De Luyck <lkml@kcore.org>]

On Tuesday 23 November 2004 22:02, Alan Stern wrote:
> On Tue, 23 Nov 2004, Jan De Luyck wrote:
> > On Tuesday 23 November 2004 20:39, Alan Stern wrote:
> > > Try the patch below and see if it helps.
> > >
> > > Alan Stern
> > >
> > >
> > > ===== drivers/usb/storage/transport.c 1.152 vs edited =====
> > > --- 1.152/drivers/usb/storage/transport.c 2004-11-14 19:41:07 -05:00
> > > +++ edited/drivers/usb/storage/transport.c 2004-11-23 14:37:40 -05:00
> > > @@ -987,7 +987,7 @@
> > >   /* Genesys Logic interface chips need a 100us delay between the
> > >    * command phase and the data phase */
> > >   if (us->pusb_dev->descriptor.idVendor == USB_VENDOR_ID_GENESYS)
> > > -  udelay(100);
> > > +  udelay(200);
> > >
> > >   if (transfer_length) {
> > >    unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
> >
> > Indeed, this solved my problems.
> >
> > Thanks a lot.
>
> Just out of curiosity, could you try using several different values in
> that udelay() statement?  Maybe 200 is larger than necessary.  If
> something like 110 would work just as well, then it would help improve the
> I/O speed.

Alan, 

Sorry for the late answer, I've been rather busy of late. Today I had the time 
to recompile and test the drive.

I'm currently using the drive with a udelay of 110, and it works without any 
problems. The transfer speed is indeed higher than with the 200msec delay ;)

Hope this helps, maybe this can now be integrated into the main kernel so 
people no longer have a problem with it :)

If you need more information, feel free to ask.

Jan

-- 
I learned to play guitar just to get the girls, and anyone who says they
didn't is just lyin'!
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